CVE-2021-47288: Linux Kernel

High severity, CVSS 7.1. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: media: ngene: Fix out-of-bounds bug in ngene_command_config_free_buf() Fix an 11-year old bug in ngene_command_config_free_buf() while addressing the following warnings caught with -Warray-bounds: arch/alpha/include/asm/string.h:22:16: warning: '__builtin_memcpy' offset [12, 16] from the object at 'com' is out of the bounds of referenced subobject 'config' with type 'unsigned char' at offset 10 [-Warray-bounds] arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [12, 16] from the object at 'com' is out of the bounds of referenced subobject 'config' with type 'unsigned char' at offset 10 [-Warray-bounds] The problem is that the original code is trying to copy 6 bytes of data into a one-byte size member _config_ of the wrong structue FW_CONFIGURE_BUFFERS, in a single call to memcpy(). This causes a legitimate compiler warning because memcpy() overruns the length of &com.cmd.ConfigureBuffers.config. It seems that the right structure is FW_CONFIGURE_FREE_BUFFERS, instead, because it contains 6 more members apart from the header _hdr_. Also, the name of the function ngene_command_config_free_buf() suggests that the actual intention is to ConfigureFreeBuffers, instead of ConfigureBuffers (which takes place in the function ngene_command_config_buf(), above). Fix this by enclosing those 6 members of struct FW_CONFIGURE_FREE_BUFFERS into new struct config, and use &com.cmd.ConfigureFreeBuffers.config as the destination address, instead of &com.cmd.ConfigureBuffers.config, when calling memcpy(). This also helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy().

Affected products

• Linux Linux Kernel: from 2.6.34, before 4.4.277 (fixed in 4.4.277); from 4.5, before 4.9.277 (fixed in 4.9.277); from 4.10, before 4.14.241 (fixed in 4.14.241); from 4.15, before 4.19.199 (fixed in 4.19.199); from 4.20, before 5.4.136 (fixed in 5.4.136); from 5.5, before 5.10.54 (fixed in 5.10.54); …

Published 2024-05-21. Last modified 2026-06-17.